Heretofore, there has been developed a fuel cell car on which a fuel cell to generate a power by an electrochemical reaction of a fuel gas (e.g., a hydrogen gas or a compressed natural gas) and an oxidizing gas (e.g., air) is mounted as an energy source. On this fuel cell car, a fuel gas tank (a gas storage container) is mounted, and the fuel gas is supplied to this fuel gas tank from a fuel gas supply system such as a gas charging apparatus (a fuel gas station). In this gas charging apparatus, a charging nozzle connected to an accumulator which stores the compressed fuel gas is usually connected to the fuel gas tank of the fuel cell car, to charge the high-pressure fuel gas into the fuel gas tank. However, when the fuel cell car includes a plurality of fuel gas tanks, a pressure and a temperature in one of the fuel gas tanks are monitored, and from this monitoring result, a fill percentage of the fuel gas tank is judged, to control the end of the charging of the fuel gas.
Moreover, there is also disclosed a gas charging apparatus comprising charging valves connected to a plurality of fuel gas tanks mounted on a fuel cell car, respectively; discharge valves connected to the plurality of fuel gas tanks, respectively; a charging piping line interposed between the charging valves; a discharge piping line interposed between the discharge valves; a plurality of temperature sensors which detect temperatures of the plurality of fuel gas tanks, respectively; a plurality of pressure sensors which detect pressures of the plurality of fuel gas tanks, respectively; and a control unit which controls the charging valves and the discharge valves based on the detection results of the temperature sensors and the pressure sensors (e.g., see JP-A-2004-84808)